From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753133Ab1AYPGS (ORCPT ); Tue, 25 Jan 2011 10:06:18 -0500 Received: from server109-228-6-236.live-servers.net ([109.228.6.236]:54655 "EHLO fireflyinternet.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751492Ab1AYPGR (ORCPT ); Tue, 25 Jan 2011 10:06:17 -0500 X-Default-Received-SPF: pass (skip=forwardok (res=PASS)) x-ip-name=78.156.66.37; From: Chris Wilson To: Knut Petersen Cc: linux-kernel@vger.kernel.org, Chris Wilson Subject: [PATCH] drm/i915/sdvo: If at first we don't succeed in reading the response, wait Date: Tue, 25 Jan 2011 15:06:07 +0000 Message-Id: <1295967967-26041-1-git-send-email-chris@chris-wilson.co.uk> X-Mailer: git-send-email 1.7.2.3 In-Reply-To: <4D3EB90C.9020901@t-online.de> References: <4D3EB90C.9020901@t-online.de> X-Originating-IP: 78.156.66.37 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org We were not pausing after detecting the response was pending and so did not allow the hardware sufficient time to complete before aborting. This lead to transient failures whilst probing SDVO devices. Signed-off-by: Chris Wilson --- Knut, this should fix one of the failures in the log: [ 680.371855] [drm:intel_sdvo_debug_write], SDVOC: W: 0B (SDVO_CMD_GET_ATTACHED_DISPLAYS) [ 680.417190] [drm:intel_sdvo_write_cmd], command returns response Pending [4] which caused the detect routine to return connector_status_unknown. However, there is still immediately following that: [ 680.419880] [drm:intel_sdvo_debug_write], SDVOC: W: 11 00 00 (SDVO_CMD_SET_TARGET_OUTPUT) [ 680.450190] [drm:intel_sdvo_write_cmd], command returns response Invalid arg [3] which implies that we are mishandling that odd VGA-2 connector. -Chris --- drivers/gpu/drm/i915/intel_sdvo.c | 23 +++++++---------------- 1 files changed, 7 insertions(+), 16 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_sdvo.c b/drivers/gpu/drm/i915/intel_sdvo.c index 45cd376..f52df3a 100644 --- a/drivers/gpu/drm/i915/intel_sdvo.c +++ b/drivers/gpu/drm/i915/intel_sdvo.c @@ -473,20 +473,6 @@ static bool intel_sdvo_write_cmd(struct intel_sdvo *intel_sdvo, u8 cmd, return false; } - i = 3; - while (status == SDVO_CMD_STATUS_PENDING && i--) { - if (!intel_sdvo_read_byte(intel_sdvo, - SDVO_I2C_CMD_STATUS, - &status)) - return false; - } - if (status != SDVO_CMD_STATUS_SUCCESS) { - DRM_DEBUG_KMS("command returns response %s [%d]\n", - status <= SDVO_CMD_STATUS_SCALING_NOT_SUPP ? cmd_status_names[status] : "???", - status); - return false; - } - return true; } @@ -505,12 +491,17 @@ static bool intel_sdvo_read_response(struct intel_sdvo *intel_sdvo, * * Check 5 times in case the hardware failed to read the docs. */ - do { + if (!intel_sdvo_read_byte(intel_sdvo, + SDVO_I2C_CMD_STATUS, + &status)) + return false; + while (status == SDVO_CMD_STATUS_PENDING && retry--) { + udelay(15); if (!intel_sdvo_read_byte(intel_sdvo, SDVO_I2C_CMD_STATUS, &status)) return false; - } while (status == SDVO_CMD_STATUS_PENDING && --retry); + } DRM_DEBUG_KMS("%s: R: ", SDVO_NAME(intel_sdvo)); if (status <= SDVO_CMD_STATUS_SCALING_NOT_SUPP) -- 1.7.2.3